Many catalytic combustion applications use liquid fuels. These fuels, however, must be evaporated prior to combustion. One method of evaporation uses a vaporizer wherein the liquid fuel is flowed through a nozzle onto a hot surface, which causes the liquid fuel to evaporate. Generally, vaporizers require large energy expenditures to maintain the temperature of the hot surface. In addition, when this method is employed with heavy hydrocarbons, such as Diesel fuels and jet propulsion fuels (e.g., JP-8, Jet A, etc.), equipment maintenance may become excessive. The nozzle, while not in contact with the hot surface, is in the presence of the hot surface therefore it gets quite hot. As a result, the liquid fuel within the nozzle decomposes thermally to form various solid deposits and/or coke. These deposits and/or coke eventually form blockages within the nozzle that foul or block the nozzle. Periodic maintenance is required to remove these blockages.
Yet another method of evaporation employs a spray atomizer. Generally, a spray atomizer is preferred for the evaporation of liquid fuel. A spray atomizer disperses the liquid fuel in fine droplets, in a process generally referred to as atomization, into a gas, such as air. The fine droplets increase the surface area of the liquid fuel, thus the interface between the gas and the liquid fuel is increased. Consequently, the evaporation rate of the liquid fuel into the gas is increased. These systems, however, create droplets of substantially different size and poorly disperse the droplets, which can effect overall combustion performance.
Based on the foregoing, it is the object of the present invention to overcome the problems and drawbacks of the prior art.